Move diff and wait to perform_action (#375)

This primarily moves the diff and wait logic from the various service
methods to perform_action to eliminate code duplication. I also moved
the diff_objects function out of the service object and moved most of
the find_resource logic to a new resource client method. We ended up
with several modules creating a service object just to use one of these
methods, so it seemed to make sense to make these more accessible.

plugins/module_utils/k8s/exceptions.py

@@ -7,4 +7,6 @@ class CoreException(Exception):
 
 
 class ResourceTimeout(CoreException):
-    pass
+    def __init__(self, message="", result=None):
+        self.result = result or {}
+        super().__init__(message)